Patent Application
20130233299
The present invention generally relates to a solar radiation collector, and more specifically, to a non-tracking solar radiation collector that is highly resistant to seismic activity and extreme weather conditions.
Solar energy is, for all intents and purposes, an inexhaustible clean energy supply that can be collected using solar thermal collection systems, for example. With the rising costs of, and competition for, increasingly scarce fossil fuel resources, solar thermal systems are becoming an increasingly attractive option for providing power at residential, commercial, industrial, and grid-level scales. However, in zones of frequent seismic activity and/or extreme weather conditions, conventional systems may be suboptimal due to the risk that such systems will be damaged before they are able to generate a reasonable return-on-investment. Furthermore, conventional solar thermal systems do not harness a broad spectrum of solar energy, instead they only make use of visible light and ultraviolet (UV) wavelengths in significant quantities.
Certain embodiments of the present invention may provide solutions to the problems and needs in the art that have not yet been fully identified, appreciated, or solved by current solar radiation collection technologies. For example, some embodiments of the present invention utilize a non-tracking design having a unique architecture that facilitates broad spectrum collection and uses one or more lenses to focus solar energy into one or more light traps. Some embodiments also have a non-tracking architecture that is also highly resistant to seismic activity and extreme weather conditions, such as hurricane-force winds.
In one embodiment, an apparatus includes a double parabolic reflector and a light trap. The apparatus also includes a lens configured to receive light from the double parabolic reflector and focus the reflected light into the light trap.
In another embodiment, a solar energy collection system includes a reflector configured to reflect a broad spectrum of solar energy and a lens or mirror configured to focus concentrated light received from the reflector. The solar energy collection system also includes a light trap configured to receive focused light from the lens or minor and a black body exposed within the light trap. The black body is configured to absorb solar energy as thermal energy and transfer the thermal energy to a thermal transfer medium.
In yet another embodiment, a system includes a reflector and a plurality of Fresnel lenses configured to receive and focus light reflected by the reflector. The system also includes a plurality of light traps configured to receive the focused light from a respective one of the plurality of Fresnel lenses.
In still another embodiment, an apparatus includes a reflector and an aerodynamic cowling configured to reduce wind resistance of the apparatus.
In another embodiment, a computer-implemented method includes automatically detecting inclement weather conditions or seismic activity that exceed a predetermined threshold. The computer-implemented method also includes modifying a physical configuration of a solar collection system, via at least one drive mechanism, to prepare the system for the inclement weather conditions or seismic activity when the predetermined threshold is exceeded.
In another embodiment, a system includes a reflector and a controller. The system also includes a drive mechanism configured to automatically alter an inclination of the reflector responsive to commands from the electronic controller such that the reflector closely tracks an azimuth of the Sun.
For a proper understanding of the invention, reference should be made to the accompanying figures. These figures depict only some embodiments of the invention and are not limiting of the scope of the invention. Regarding the figures:
It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments, as represented in the attached figures, is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.
The features, structures, or characteristics of the invention described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of “certain embodiments,” “some embodiments,” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. Thus, appearances of the phrases “in certain embodiments,” “in some embodiments,” “in other embodiments,” or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Some embodiments of the present invention are directed to non-tracking solar collectors that may be highly resistant to seismic activity and extreme weather conditions. The solar collection panels in some embodiments are unique in that they are as strong as, or stronger than, conventional metal panels, but are composed of light structural plastics that act as a dampening agent, as well as provide a stable platform for precisely focusing solar energy for solar thermal applications. Although metals such as aluminum may be used for some components and framing, the weight of embodiments of the present invention tends to be significantly less than conventional solar thermal systems.
In some embodiments, the panels are covered with a highly solar reflective film that reflects a broad spectrum of solar energy to a high degree. In certain embodiments, reflectivity in the infrared, visible light, and ultraviolet (UV) ranges may exceed 90% across most wavelengths. Some of these concepts are discussed in more detail in parent U.S. patent application Ser. No. 13/417,133.
Panels in some embodiments of the present invention provide a greater amount of thermal energy than conventional systems, yet are approximately the same weight as a typical high quality photovoltaic panel, without the complexity and durability issues. In other words, some embodiments of the present invention both collect more energy and cost considerably less than conventional systems.
Some embodiments use structural plastic foam for panel construction. Foams such as acrylonitrile-butadiene-styrene (ABS) foams may be suitable for many embodiments. These foams have proven strength and durability and are used frequently in the automotive industry. ABS plastics can be molded into complex reinforced shapes that are stronger than steel. Further, ABS foams present a less expensive, stronger, lightweight alternative to metals in the construction of broad spectrum solar collection assemblies.
Most advanced solar thermal technologies include components that are relatively massive. Because of their size, these components require stout foundations and must be designed to manage substantial wind loads. These assemblies typically only meet the standards for minimum seismic loading. Further, these assemblies will generally not survive extremely strong winds, such as those generated by strong hurricanes and typhoons.
These considerations have limited locations in the world where concentrated solar thermal systems can be deployed. Photovoltaics have dominated rooftop and urban deployments. However, advanced solar thermal systems generally have a larger solar operating window. Most have some storage capabilities, but the limitation of the sheer mass of the typical concentrated solar thermal system causes this advantage to be forsaken since concentrated solar thermal systems are not suited for the vast majority of urban settings.
There is a need for solar thermal solutions for environments that experience high winds, violent storms, and other forms of severe weather. Islands in the Caribbean and parts of the southeastern United States, for instance, experience hurricanes more frequently than many other areas. Many parts of the Caribbean, in particular, are desperately in need of stable and economical energy sources. Similarly, there is a need for solar thermal systems in areas with significant levels of seismic activity. For example, the Japanese Government is aggressively searching for replacements for its nuclear power systems. Some embodiments of the present invention can be deployed in areas where there is a serious danger of seismic activity or inclement weather. Broad spectrum solar thermal systems, such as those discussed in the present application and parent application, have significant advantages over other energy collection technologies in that they are green, collect energy at any time of the day regardless of cloud cover, and may be manufactured and deployed at relatively low cost.
Some embodiments of the present invention may be used in a parabola trough or a deep elliptical-shaped dish. The panels of these embodiments may be covered in a highly solar reflective film that reflects a broad spectrum of solar energy. Embodiments also generally use light traps having black bodies. However, in order to accommodate the Sun's daily movement across the trough or dish's reflective surface, lenses and clusters of light traps with black bodies may be used. In many embodiments, Fresnel lenses may be particularly useful due to their compact size. A Fresnel lens generally is divided into a set of concentric annular sections with a nearly flat convex center. Such lens designs may be found in the headlamps, brake lights, and turn signal lights of many automobiles, for example.
One unique aspect of this family of dishes is that they can be configured in a similar fashion to solar photovoltaic panels due to the low weight. In fact, such collectors can be sized to directly compete with solar photovoltaic (SPV) panels and have the further benefit of the production of thermal energy, and potential thermal storage. This thermal energy may then be used directly, or used to generate electricity by creating steam and driving a generator, for instance. Such solar thermal systems exhibit distinct advantages over SPV systems, particularly for air conditioning and heating applications. Rooftop concentrated solar thermal systems are possible with these dishes.
Because some embodiments of the present invention only need to be adjusted to follow the Sun's azimuth, these embodiments need to move on only one axis. Generally, most embodiments should be aligned in a specific direction when collecting solar energy in order to optimally track the azimuth of the Sun, as well as to allow the dish shape to collect radiation anywhere along the Sun's elevation. Some embodiments may be aligned so as to always face this direction, and other embodiments may be configured to rotate such that they can face in this direction, or in another desired direction. For locations where there is the potential for severe weather, these systems can be covered in a manner that provides a wind-deflecting shape with an aerodynamic cowling that, when in a lockdown position, creates an aerodynamic “teardrop” shape and may be free to rotate to self-orient into an optimal or near-optimal wind deflecting position. Particularly, such designs can be lowered into storm bunkers, which can rotate and adjust position so as to present the most aerodynamic shape to the oncoming wind when the need arises, which changes the dish's effective shape from a circular ovoid egg shape to a teardrop.
Because of the low weight and extremely good strength-to-weight ratio of some embodiments, foundations can be designed to accommodate the movement of the Earth even during severe earthquakes. The system literally “floats” on top of the quake since the various sections have the freedom to move, and are designed to return to the correct position after the initial quake and subsequent aftershocks have subsided.
Some embodiments may be deployed as panels that can be sized such that assembly by hand is possible. These panels may interlock and may be easily assembled on a frame made from a material such as aluminum, for example. The interlocking of some embodiments is better illustrated in
For the transport of collected thermal energy, some embodiments use a solid state thermal transport system, with proximity heat exchangers to accommodate moving joints. The system may use a graphite composite thermal transfer medium such as PocoFoam® in some embodiments. Some embodiments also use thermal expansion-driven switches similar to those described in U.S. patent application Ser. No. 13/326,454, which is incorporated herein by reference.
Left parabola 112 and right parabola 114 are shaped such that a majority of the solar energy striking the surface thereof is reflected into light trap 120. This is regardless of the angle of incidence of photons striking the reflective surface. In
In some embodiments, light trap 220 may be consistent with the light traps described in the parent application. Solar energy passes through Fresnel lens 210 and is focused through focal point F into light trap 220. f is the focal length of Fresnel lens 210, and lens power P is determined by
In some embodiments, light trap 220 may contain two opposing elliptical minors that concentrate the majority of solar energy entering light trap 220 onto a black body 222.
Black body 222 may include a high temperature ceramic mixture of zirconium diboride (ZrB2), possibly in a mixture of silicon carbide (SiC), or pure ZrB2 coated with a thin coating of various ceramics such as cubic boron nitride (BN), or other materials such as stabilized zirconium dioxide (ZrO2). Black body 222 absorbs solar energy that enters light trap 220 and converts the absorbed solar energy into thermal energy. Black body 222 is integrated with a solid state thermal transfer medium 230 that may include a graphite foam material such as PocoFoam®. Thermal transfer medium 230 transfers heat away from black body 222 for subsequent use, such as for direct heat applications, to heat water for purposes such as electrical generation, for storage in a thermal storage medium such as those discussed in U.S. patent application Ser. No. 13/361,877, which is incorporated herein by reference, or for any other suitable use.
Each of Fresnel lenses 320, 322, 324, and 326 is positioned so as to focus solar energy into a respective light trap 330, 332, 334, and 336. While four light traps and Fresnel lenses are shown in
A thermal transfer conduit 350 containing a thermal transfer medium such as PocoFoam® is positioned in between light traps 330, 332, 334, 336, and the thermal transfer medium is operably connected to each of black bodies 340, 342, 344, and 346 (not shown). In some embodiments, thermal transfer conduit 350 may run the length of the trough. Also, while shown running horizontally here, in some embodiments, thermal transfer conduit 350 may run vertically.
An aerodynamic cowling 410 surrounds linear trough 420. Aerodynamic cowling 410 may be oval shaped, egg shaped, or any other shape suitable for withstanding strong prevailing winds in some embodiments. Further, in some embodiments, the entire assembly may be moved so that aerodynamic cowling 410 presents a more narrow profile in the general direction of the wind.
A base 550 supports a fulcrum 552 that permits a lever arm 554 to move in a vertical direction. Lever arm 554 is counterbalanced by a counterweight 556. A foundation bunker 560 allows retraction of cowling 510 and double parabola trough 520 to form a teardrop shape. This vertical movement is enabled by a hydraulic lift 570.
The aerodynamics of the shape of solar energy collection system 500 are easier to manage in high winds. Further, it is generally optimal for double parabolic trough 520 to be oriented to the Sun's in a permanent alignment position with respect to the Sun's elevation and adjust the angle of the azimuth. This requires double parabolic trough 520 to be inclined, which is accomplished by hydraulic lift 570. Generally speaking, the highest angle of inclination should be at the Winter Sol Invictus and the lowest angle of inclination should be at the Summer Solaces.
An electronic controller 580 controls hydraulic lift 570 in order to change the angle of inclination of double parabolic trough 520. Electronic controller is also connected to monitoring equipment 590 in this embodiment. Monitoring equipment 590 may be in any suitable location and may communicate with electronic controller 580 through a wired connection, wirelessly, via an intermediary device, or by any other suitable means. Monitoring equipment 590 may include a seismometer, a barometer, an anemometer, and/or any other device for detecting weather conditions and seismic activity. When weather conditions and/or seismic activity exceed a certain threshold, electronic controller 580 may move double parabolic trough 520 accordingly. For instance, in strong winds, double parabolic trough 520 may be positioned horizontally so as to present a smaller profile. During an earthquake, double parabolic trough 520 may be inclined significantly away from the azimuth so large amounts of energy are not being collected. In certain embodiments, double parabolic trough 520 may be moved as far away from the azimuth as possible and/or the light traps or lenses may be turned so as to reflect light back into the atmosphere. This motion could, for example, be accomplished by a simple servo. In some embodiments, double parabolic trough 520 may retract into a bunker.
Non-transitory computer-readable media may be any available media that can be accessed by processor 1010 and may include both volatile and non-volatile media, removable and non-removable media, and communication media. Communication media may include computer-readable instructions, data structures, program modules, lookup tables, or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.
Processor 1010 is further coupled via bus 1005 to a display 1025, such as a Liquid Crystal Display (“LCD”), for displaying information to a user. A keyboard 1030 and a cursor control device 1035, such as a computer mouse, are further coupled to bus 1005 to enable a user to interface with controller 1000. Display 1025, keyboard 1030, and cursor control device 1035 may be located separately from controller 1000 and may communicate with controller 1000 via wireless communication, an Ethernet cable, or any other suitable means for transmitting and/or carrying data. For instance, a common control center may be used to control multiple solar energy collection devices.
In one embodiment, memory 1015 stores software modules that provide functionality when executed by processor 1010. The modules include an operating system 1040 for controller 1000. The modules further include an inclination control module 1045 that is configured to at least control the inclination of a solar collector. However, other functionality, such as lens and light trap orientation, for example, may also be controlled as a matter of design choice. Controller 1000 may include one or more additional functional modules 1050 that include additional functionality.
One skilled in the art will appreciate that a “controller” could be embodied as a personal computer, a server, a console, a personal digital assistant (PDA), a cell phone, or any other suitable computing device, or combination of devices. Presenting the above-described functions as being performed by a “controller” is not intended to limit the scope of the present invention in any way, but is intended to provide one example of many embodiments of the present invention. Indeed, methods, systems and apparatuses disclosed herein may be implemented in localized and distributed forms consistent with computing technology.
It should be noted that some of the controller features described in this specification have been presented as modules in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very large scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays (FPGAs), programmable array logic, programmable logic devices, graphics processing units, or the like.
A module may also be at least partially implemented in software for execution by various types of processors. An identified unit of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions that may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. Further, modules may be stored on a non-transitory computer-readable medium, which may be, for instance, a hard disk drive, flash device, random access memory (RAM), tape, or any other such medium used to store data.
Indeed, a module of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.
Upper base portion 1120 is seated upon hydraulic lift 1130. In some embodiments, hydraulic lift 1130 may be configured to raise and lower the entire reflector assembly into a lockdown position, tilt the reflector assembly, etc. Hydraulic lift 1130 is seated upon a first lower base portion 1140, which is operably connected to ball bearings 1170. However, in some embodiments, ball bearings 1170 may be connected to second lower base portion 1142, or to neither first lower base portion 1140 nor second lower base portion 1142. Ball bearings 1170 sit upon, or within a track or groove of, second lower base portion 1142, forming a turntable. However, in some embodiments, the track or groove may be in first upper base portion 1140. Second lower base portion 1142 rests upon a foundation 1180 within bunker 1150.
In
Bunker 1150 may be fabricated from concrete foam or from any other suitable material. Individual pieces, or blocks, of bunker 1150 may have a key-lock configuration similar to that of
Rotation may be accomplished by ball bearings 1170, or by any other suitable mechanism such as an oiled low-friction track or magnetic levitation (mag-lev) similar in principle to the operation of certain trains, and all such mechanisms of rotation are included within the definition of a “turntable” as described herein. Ball bearings 1170 may provide reasonable resistance such that the rotation will be moderate. Ball bearings 1170 may be seated in a track or groove of second lower base portion 1142, or otherwise positioned so as to enable rotation of a turntable. While rotation in certain embodiments may be controlled by a drive mechanism, freely rotating embodiments may provide superior performance and be more cost-effective due to reduced machinery and complexity. It may be complex to predict winds in areas where rapidly circulating winds are common, and it is particularly complex to predict swirling winds in powerful storms such as hurricanes, typhoons, tornadoes, and strong thunderstorms. Rather, it may be better to let the entire bunker freely rotate with the wind and optimally position itself.
Some of the modifications that may be made in some embodiments include rotating the solar collection system so as to present a lower profile to the wind, moving a reflector to a horizontal position when the wind speed exceeds a predetermined threshold, altering an inclination of the reflector, a direction of a mirror, or a direction of a light trap when seismic activity exceeding the predetermined threshold is detected, and lowering the solar collection system at least partially into a bunker. Once modified, the system tracks whether the weather conditions or seismic activity have fallen below the predetermined threshold at 1240. If not, the system stays in the protected configuration. If below the threshold, the system returns to the normal configuration at 1250 and the process ends.
The method steps performed in
The computer program can be implemented in hardware, software, or a hybrid implementation. The computer program can be composed of modules that are in operative communication with one another, and which are designed to pass information or instructions to display. The computer program can be configured to operate on a general purpose computer, or an application specific integrated circuit (“ASIC”).
Some embodiments of the present invention are directed to a solar collector that reflects a broad spectrum of solar energy and focuses the solar energy through one or more lenses. The one or more lenses then direct the focused solar energy into one or more light traps where a black body absorbs a large portion of the solar energy and converts it into thermal energy. The thermal energy is then transferred via a thermal transfer medium for subsequent use, such as for storage in a thermal storage unit or for direct use to heat water, for example.
In some embodiments, the solar collector may have an aerodynamic design that is configured to resist high levels of wind. Such embodiments may have an aerodynamic cowling that may offer low wind resistance and may be positioned so as to present a low profile to the wind. In some embodiments, the inclination of the system may be changed to track the azimuth of the Sun and/or to move the inclination away from the azimuth in the event of an earthquake.
One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims.
This application is a continuation-in-part of, and claims priority to, U.S. patent application Ser. No. 13/417,133, filed Mar. 9, 2012. The subject matter of this earlier filed application is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13417133 | Mar 2012 | US |
| Child | 13434953 | US |
